Electrospun poly(vinyl alcohol) composite nanofibers with halloysite nanotubes for the sustained release of sodium d -pantothenate

Poly(vinyl alcohol) (PVA) nanofibers containing halloysite nanotubes (HNTs) loaded with sodium d-pantothenate (SDP) were successfully fabricated via simple blend-electrospinning. SDP was efficiently loaded into the innate HNT lumen with an SDP/HNT mass ratio of 1.5:1 via vacuum treatment. The SDP-loaded HNT-inclusion complex was evaluated with drug-loading efficiency testing, Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction. The morphologies of the nanofibers were observed by scanning electron microscopy, which revealed uniform and smooth surfaces of the nanofibers. The addition of HNTs to the composite nanofibers increased the viscosity of the polymer solution, and this suggested shorter fiber diameters. FTIR spectroscopy verified the good compatibility of the SDP and HNTs with PVA. Moreover, the swelling properties were found to quantitatively correlate with weight loss. In vitro drug-release testing revealed that the HNTs and crosslinking reaction most dramatically affected the sustained release of SDP from the PVA and SDP-loaded HNT complex. In the drug-release kinetics model, SDP release depended on the diffusion caused by the deformation of the polymer-based structures in the medium; it followed Fickian diffusion with acceptable coefficient of determination (r²) values between 0.88 and 0.94. Most importantly, the HNTs as natural biocontainers effectively modulated the release profile by loading the active compound in harmony with the electrospun nanofibers.